1. Field of the Invention
The present invention relates to driving apparatus and method for a hybrid vehicle in which a motor/generator is equipped to regenerate an energy and to assist an engine output.
2. Description of the Related Art
A Japanese Patent Application First Publication No. Heisei 9-98516 published on Apr. 8, 1997 exemplifies a first previously proposed driving apparatus for the hybrid vehicle.
In the first previously proposed driving apparatus, a driving point of an engine in the hybrid vehicle is selected from either one of the driving points at which a fuel consumption is best (viz., approximately minimized) or at which an exhaust gas quantity is approximately minimized and a transmission and the motor/generator are operated to achieve this requirement.
On the other hand, a Japanese Patent Application First Publication No. Heisei 9-238403 published on Sep. 9, 1997 exemplifies a second previously proposed driving apparatus for the hybrid vehicle in which the motor/generator is equipped and is associated with a Diesel engine.
In the second previously proposed driving apparatus, the motor/generator is controlled to generate a power by means of an extra torque of the engine during a normal (or a steady-state) vehicular run so as to regenerate an energy and is controlled to assist an engine output during a vehicular acceleration.